A pressure-sensitive adhesive (PSA) can be a viscoelastic (viscous and elastic) substance capable of forming a bond with an adherent upon the application of pressure. A PSA can be soft enough to flow, or wet, but hard enough to resist flow when stress is applied. Pressure-sensitive adhesives can provide advantages over other adhesives inasmuch as they do not require cure time and other processing steps often required with the use of other adhesives.
Commercially available PSAs often include polymers such as natural rubber, polynitrile, acrylic, isobutylene, silicone and styrene. Typically, these PSAs are made from petroleum sources, have attractive fiber and structural properties, are low in cost and are easily processed. One disadvantage with many PSAs, however, is that they fail to degrade into components that can be metabolized by microbial populations or in vivo. Such PSAs are thus limited in their use in biomedical applications and other applications for which a biocompatible or biodegradable PSA would be useful.